• Journal of Microbiology and Biotechnology
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• 제24권12호
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• pp.1664-1672
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• 2014

In this study, a fibrous bed bioreactor (FBB) was used for $\small{D}$-lactic acid ($\small{D}$-LA) production by Sporolactobacillus inulinus Y2-8. Corn flour hydrolyzed with ${\alpha}$-amylase and saccharifying enzyme was used as a cost-efficient and nutrient-rich substrate for $\small{D}$-LA production. A maximal starch conversion rate of 93.78% was obtained. The optimum pH for $\small{D}$-LA production was determined to be 6.5. Ammonia water was determined to be an ideal neutralizing agent, which improved the $\small{D}$-LA production and purification processes. Batch fermentation and fed-batch fermentation, with both free cells and immobilized cells, were compared to highlight the advantages of FBB fermentation. In batch mode, the $\small{D}$-LA production rate of FBB fermentation was 1.62 g/l/h, which was 37.29% higher than that of free-cell fermentation, and the $\small{D}$-LA optical purities of the two fermentation methods were above 99.00%. In fe$\small{D}$-batch mode, the maximum $\small{D}$-LA concentration attained by FBB fermentation was 218.8 g/l, which was 37.67% higher than that of free-cell fermentation. Repeate$\small{D}$-batch fermentation was performed to determine the long-term performance of the FBB system, and the data indicated that the average $\small{D}$-LA production rate was 1.62 g/l/h and the average yield was 0.98 g/g. Thus, hydrolyzed corn flour fermented by S. inulinus Y2-8 in a FBB may be used for improving $\small{D}$-LA fermentation by using ammonia water as the neutralizing agent.

• Journal of Dairy Science and Biotechnology
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• 제22권2호
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• pp.91-97
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• 2004

활성산소의 세포막 파괴 효과로부터 보호작용과 항산화 활성이 강한 균주를 선별하기 위하여 33균주에 대한 세포네 glutathione 함유율과 linoleic acid 산화억제활성을 측정하였다. Lactobacillus casei CU4114 25.15 umol/g으로 가장 높은 함유율을 보이고 있으며Lactobacillus rhamnosus CU4201, Lactobacillus plantarum CU4203이 14.0umol/g으로 통계적인 유의성을 나타내는 수준으로 높은 함유율을 나타내었다. 포자형 성균주중의 glutathione 함유율 측정 결과 Lactobacillus sporogenes CU4109, Sporolactobacillus inulinus CU4110 은 Bacillus coagulans 균주의 GSH 함유율보다 유의성이 인정되는 높은 함유율을 나타내었다. L. acidophilus CU4111, L. casei CU4114, L. brevis CU4206, L. helveticus Cu4231은 Lactobacillus spp. 중 높은 항산화 활성을 나타내었고 Bacillus coagulans의 항산화 활성범위는 6.02${\sim}$51.72%로 나타났으며 Bacillus coagulans 균주의 항산화 활성이 Lactobacillus spp.의 산화억제활성보다 높은 성향을 나타내었다.